The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Vehicles with a DCT transfer an engine torque to a transmission by selectively controlling two dry clutches. The dry clutch may easily generate heat due to a clutch slip and heated heat sources are slowly cooled by convection based on an air cooling method.
However, when a clutch is controlled to continuously bring about the clutch slip even under the condition that the dry clutch continuously generates heat, the dry clutch reaches an area in which a friction characteristic of a friction surface of the dry clutch is lost and finally loses the friction characteristic of the clutch, such that clutch hardware may fail.
In determining the slip which is an important factor of the heat generation of the clutch, hybrid type vehicles with the DCT determine the slip by comparing a speed detected from an input shaft speed sensor installed in the transmission with a motor speed input from a driving motor. Therefore, the two speed signals are used as an input signal in protecting the clutch.
Therefore, when the motor speed input from the driving motor is inaccurate, the clutch slip may not be accurately determined. Therefore, even when the abnormality of the motor speed is detected, overheating of the clutch is unavoidable.